1. Field of the Invention
The present invention relates to a system and method for drawing a stream and road centerline for Geographic Information System (GIS)-based linear map production, and, more particularly, to a system and method for drawing a stream and road centerline for GIS-based linear map production, which performs a series of processes of automatically detecting accurate positions of points on a centerline using contour line data of a stream map or a road map having a digital map form, which is extracted from a digital map produced through remote sensing or construction of national geographic information systems, and connecting the detected points of the centerline so as to update stream and road centerline data generated by an inaccurate method and algorithm of the related art and to enable an accurate centerline to be used in various application fields.
2. Description of the Related Art
As known, in a current system used in a computer, in order to produce or update a small-scale map using a large-scale map, linear targets such as streams or roads need to be generalized from a polygon to a line, due to a limit in target size capable of being expressed in the small-scale map.
Therefore, various methods or algorithms for generalization have been developed. However, since the centerline of each object which is drawn when the large-scale map is produced is used in the linear expression of the small-scale map without change or with change, the drawing of the accurate centerline when the large-scale map is produced is of importance.
In addition, recently, a linear map is applied to a GIS technology so as to be widely used in many application fields. A stream centerline is used as reference data in water-flow distance calculation, network analysis, stream shape change sensing and monitoring, water quality simulation section determination, and a road centerline is used as reference data in distance and required time calculation of vehicle navigation and optimal route determination. The applicability of the linear map has been gradually increased.
However, the existing stream or road centerline is not drawn so as to accurately pass through a central portion accurately corresponding to half of the width of an object, but is drawn so as to pass through a substantially central portion of an object by qualitative judgment or a personal criterion of a mapper. That is, since the existing stream or road centerline is not drawn based on a strict criterion, there is a limit in that the existing stream or road centerline is used as reference data of the accurate analysis or use. In addition, the existing stream or road centerline may cause an unintended result.